


Binary Stars Make Gravitational Waves

by ColorsofaYinYang



Series: Nostalgia Challenge [2]
Category: Kingdom Hearts
Genre: Alternate Universe - Aliens, Alternate Universe - Modern Setting, Alternate Universe - Roommates/Housemates, Angst, Everyone Is Gay, F/F, Fluff, Found Family, Humor, M/M, Slow Burn
Language: English
Status: In-Progress
Published: 2020-05-16
Updated: 2020-05-16
Packaged: 2021-03-02 22:54:01
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,362
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24174667
Author URL: https://archiveofourown.org/users/ColorsofaYinYang/pseuds/ColorsofaYinYang
Summary: Zexion laces his fingers together, staring Demyx down from across the table. “You’re an alien.”Demyx laughs, feeling his gills flap nervously under his scarf. “Haha, nope, 100% human, what makes you think that?”
Relationships: Axel/Roxas (Kingdom Hearts), Demyx's Somebody/Ienzo (Kingdom Hearts), Demyx/Ienzo (Kingdom Hearts), Demyx/Zexion (Kingdom Hearts), Naminé/Xion (Kingdom Hearts), Riku/Sora (Kingdom Hearts)
Series: Nostalgia Challenge [2]
Series URL: https://archiveofourown.org/series/1699375
Comments: 2
Kudos: 6





	Binary Stars Make Gravitational Waves

**Author's Note:**

> Inspired by this prompt from writing-prompts-s on Tumblr:
> 
> Four roommates are extraterrestrials who have taken human form in the hopes of learning about Earth’s culture. Unfortunately, each alien is from a different planet and believes the other three are normal humans. 
> 
> There will be some worldbuilding stuff in the end notes of each chapter if anyone's interested.

**Notes for the Chapter:**

> Zexion is a manipulative little shit and I love him to death.

Okay, Demyx _swears_ he didn’t mean to crash-land on this planet. So maybe he skimped and put some cheap, used parts he had bought off the black market into his ship instead of the Polluxan brand ones Luxord had recommended, and _maybe_ he had panicked a little when the red light started blinking, signalling something seriously wrong with the engine. It definitely wasn’t his fault that the only place hospitable enough to survive on also had an extremely unfriendly atmosphere that had burnt the outer shields to a crisp, leaving him with no protection for when he had slammed the ship into the side of a mountain in an attempt to land it. 

But Xigbar doesn’t seem to understand this. Their captain’s been swearing at him for the past half hour over the radio, while Luxord cackles in the background. Xaldin’s as quiet as ever, so Demyx can’t even tell if he’s there or not. He sits slumped on a tree stump, stares at the flaming wreckage of his ship and groans.

“C’mon, boss, give the kid a break,” Luxord finally says, still chuckling a bit. “We all knew he wasn’t the best pilot to begin with.” There’s a tapping sound, as if he’s checking the radio. “So where are you now?”

Demyx shrugs, knowing full well they can’t see him. “I think I was somewhere around Jenei-1? The third or fourth planet from it. It’s covered in water, you can’t miss it.”

“Inhabited?” Xaldin asks in the background. His voice is faint, just barely audible.

“Looks like it. Probably not dangerous, though. I hope.” Demyx kicks a rock that was near his feet. Xigbar sighs.

“That’s pretty far out of the way…” Demyx’s eyes widen, and he almost squawks in indignation. “But you _are_ a good crewmember. So we’ll see what we can do.”

Immediate forgiveness. “Aw, thanks Cap!”

“You should probably hide your fins and stuff. I heard the things that live there are called “humans,” but I don’t know much about them. Find a place to take shelter for a while. We’ll drop by on the way back from the Proxima heist.” 

Demyx nods, grinning. “Will do! See you guys then. Over and out.” He switches off the radio and stands, shivering as a cold gust blows past him. His skin goosebumps, not used to the sensation of wind. He carefully picks through the remains of his ship, managing to find the emergency stash underneath the scattered debris. Inside the little pack is a warm cloak, which he wraps around himself, and a scarf to protect the gills on his neck.

A voice speaks behind him, tone dry and amused. “I wasn’t expecting to find a half-naked man in the woods today.” He jumps and spins around to find a being very similar in shape to his own, with dark hair spilling over half of their face. “You lost?”

“Um.” Demyx blinks, mind racing for an answer. He looks down at himself, making sure that none of his tibial fins are exposed. He looks up. The stranger is watching him, waiting patiently for an answer. “Yeah, I crashed my, uh… _vehicle_.” He gestures behind him to the wreckage, praying humans have similar transportation. The stranger smiles, mouth a grim slash across their face. 

“I see that.” They put their hands in the pockets of their black coat. “I can call a towing company for you, if you’d like.”

“I don’t have insurance,” Demyx blurts. _Do they even have “insurance” here?_ The stranger shakes their head dismissively.

“I know someone. He’ll move it free of charge.” The stranger pulls out their little communication device, holding it up to their ear. “Lexaeus. Yes, there’s a man here who’s crashed. Could you come pick up the wreck, please.” They rattle off some coordinates that fly right over Demyx’s head, then they hang up. “He’ll be here in a bit. For now, I’ll take you back down the mountain.” They look Demyx up and down. He shrinks a little at the scrutiny. “You’re not injured, are you?”

“Nope!” The other nods approvingly. 

“All right. Well, follow me.” They turn and start walking through the trees, steps careful and assured. Demyx hesitantly follows, picking at the straps of his pack. Every so often he catches a glimpse of the bright blue sky above through the leaves, and it startles him every time. “What is your name?” The stranger asks. 

“I’m Demyx. And you?” _It’s probably safe to ask that since it was asked of me first, right?_

“My name is Zexion.”

“Oh, cool, nice to meet you. Um, not to be rude or anything, but… what gender are you?” _Do they have gender here? Being culturally aware is so hard._ Zexion chuckles quietly.

“How considerate of you to ask. I am a male, but I can understand why you’d be confused.” Zexion pauses for a moment, surveying their surroundings, before taking a hard right. “This way.” 

The forest gradually becomes less dense until they eventually come to a road. A few meters down there are two black vehicles parked one in front of the other. “The one in front’s my car,” Zexion says. “Looks like Lexaeus is already here.” He doesn’t sound surprised at all, but Demyx doesn’t think anything of it. “We must have passed him on our way here. Oh well.” He holds open the passenger door and gestures for Demyx to get in. “You look hungry. I have food at my house that you can eat.” 

“Oh, okay, thanks!” _Huh, Zexion’s really nice,_ Demyx thinks. The other man starts the car and they accelerate off. The ride into town is quiet, which is great because Demyx is busy taking in all the sights of the world he’s crashed into. The flora is extraordinary, trees reaching into the heavens and fields of wheat and flowers reminding him of the kelp forests and anemone beds of his home planet. He even spots a group of large, four-legged animals with long hair and tails that race alongside them as the car zips past. 

As they get closer to their destination the car slows, and Demyx can read the sign that says “Welcome to Twilight Town” in big, chunky, faded red letters. A huge clock tower looms overhead as they navigate the narrow cobblestone streets. Finally, Zexion pulls to a stop next to the curb of a pretty white house, and turns off the engine. “All right, let’s go in.”

Demyx gets distracted for a second by the birds flying overhead, then tears his eyes away from them and follows the dark-haired man inside. Zexion gestures for him to take a seat at the table, then starts rummaging around in a strange humming cabinet. “Would you like something to drink?” he asks, not turning around.

His skin _is_ starting to feel a bit dry. “Do you have water?” Demyx asks. Zexion hands him a bottle and he drinks gratefully. While the other isn’t looking, he also drips some onto his gills and the moisture pads on the insides of his wrists. 

“Anything you’d prefer to eat?” Zexion asks, sliding into the chair across from him. “I must have eaten the leftovers from yesterday, so I don’t have anything on hand.” He studies Demyx closely. “What is your favorite food?”

“I like fish,” Demyx offers. Frankly, after years of being in space he’s learned to take whatever he can get, but fish and seaweed are still his favorites. “That alright?”

“Perfectly. Sushi is fine then, I take it?” Demyx nods despite not knowing what the hell sushi is. “I’ll ask the restaurant to have it delivered here. A moment, if you will.” There’s a hint of a smile on Zexion’s face as he moves into the next room over with his cellular device, leaving Demyx to take in the house around him.

The counter is clean and polished, and the cabinets host a variety of fastidiously organized dishware. The humming cabinet piques his curiosity; upon peering inside, he discovers that the interior is somehow magically cold. Another contraption built into the wall turns out to be something he recognizes (a microwave), although it seems to be much less powerful than the one the Captain uses to cook his steaks. The whole kitchen is streamlined and simple, with no extraneous decoration or even comforts like hand soap, almost as if it’s not used very often.

He quickly sits back down once Zexion’s voice stops coming from the other room, resisting the urge to look around further. The dark-haired man re-enters the kitchen and takes his seat once more. He laces his fingers together, staring Demyx down from across the table. “So. Let’s get this out of the way, first. You’re an alien.”

Demyx forces a laugh, feeling his gills flap nervously under his scarf. “Haha, nope, 100% human, what makes you think that?” Zexion leans back in his chair, bemused. 

“You’re not a very good actor.” He casually pulls out a clipboard and licks his finger, flipping through the pages. “Now tell me, what exactly are you? Yvagan? Veletian? Polluxan?” 

Having been found out, Demyx slumps down into his seat and groans. “Eridani,” he mumbles. Zexion raises an eyebrow and scribbles something down.

“That’s new. Please, tell me more about your planet.” Demyx pouts.

“Aw, c’mon Zexy! I won’t cause any trouble, I promise!” Zexion gives him a deadpan look. “I’m sorry for lying to you,” Demyx tries. “I was just gonna wait it out here until my crewmates come to pick me up, that’s all.”

“Oh, crewmates? And where are they from?” 

Demyx thinks. “Well, Luxord’s Perwanan. Xaldin said he’s Veletian. I think Cap’n is Hypatian, but I never really asked so I’m not sure.” 

“Hypatian’s are the warmongering ones, correct?” Zexion makes a few more notes, blowing some hair out of his face. 

“Yeah, but our captain’s never been that way. I think he defected a long time ago. I mean, it’s not like the empire told him to be a pirate-” He stops. “Hey, wait, don’t I get to ask some questions too?”

“What would you like to know?” Zexion asks, not looking up from his clipboard. Demyx’s mind blanks; he hadn’t expected that answer.

“Ummmm…” He sits up. “I know! How do you know about other planets? Like, no offense but I thought this place was pretty undeveloped.”

Zexion scoffs. “Well, most of the population is unaware of your existence, so your guess is close to the mark.” He tucks his pen behind his ear. “Earth is a tiny, relatively primitive planet on the outskirts of the galaxy. The perfect place for refugees. I’m a researcher working for a very specific branch of the government here, and as such I have access to the many projects my...” He pauses, as if searching for the right word, “mentor has worked on.”

A bell chimes pleasantly overhead. Curious, Demyx follows Zexion to the door and awkwardly hovers behind him as he unlocks it. A disgruntled looking blonde is standing there cradling a packed paper bag in the crook of his elbow whilst trying to tap something out on his cellular device.

“Using your phone while you’re on the job?” Zexion tsks at him, raising an eyebrow. _Is that what those devices are called?_ “You should know better than that, Roxas.”

“You try running around town all day and see if you don’t want a moment to yourself,” Roxas retorts. He finally looks up from the screen to hand Zexion the bag, then does a double take at the sight of Demyx. “Who are you?”

“This is Demyx,” Zexion smoothly cuts him off from saying anything and gives him a warning look. “He’s visiting from out of town. Demyx, this is Roxas, Twilight Town’s resident delivery boy.”

“I’m not a boy anymore, I’m 21,” Roxas grouses. He gives Demyx a once-over. “So where are you from?”

“Um…” Demyx looks to Zexion for help but the dark-haired man is busy peering into the bag, checking the order to make sure everything is right. “It’s, uh, kinda far from here. You’ve probably never heard of it.” 

“Try me.” The guy’s persistent, Demyx’ll give him that. 

“He’s a California boy.” Zexion takes mercy on him, rolling the top of the bag back up and handing Roxas a few bills. “One of those small towns east of LA.”

Roxas counts the money and tucks it into his pocket. “Huh. Well, explains the rockstar haircut.” Demyx’s hand flies up to self-consciously touch the strands falling in his face. “We still on for Saturday?”

“Of course,” Zexion replies. Roxas nods.

“Cool. See you then.” He turns to go. “Nice meeting you, Demyx,” he tosses over his shoulder. For the second human Demyx has ever met, Roxas seems pretty nice.

As soon as the blonde leaves Zexion ushers Demyx back inside and re-locks the door, placing the bag of food on the kitchen counter. He pulls out three containers of raw sliced fish on some sort of grain and slides them across the table. “So, I think we should discuss the terms of your stay here on Earth…” He observes Demyx as he pokes the “sushi” curiously, as if expecting that it’ll bite, before chomping down on one. “We can provide monetary support as well as a place to stay for the time being, but in return you must help us with our research. Is that acceptable?”

“Sure, sounds good,” Demyx replies around his mouthful. “Wait, you’re not going to like, dissect me, right?”

“As much as I’d like to, no.” Zexion smiles dryly. “It wouldn’t do well to have my only source of information dying on me due to complications, would it?” His tone registers as vaguely threatening, but Demyx ignores it because _damn_ he hasn’t had fish in so long!

“Alright, so where am I staying? Here?” 

The other man seems surprised by the lack of a response. “Er, no. There’s a house that I’ve rented for some of our other otherworldly visitors. You’ll have to share with two others, though.” He shifts in his seat and brushes the hair out of his eyes. “When you’re finished, I’ll escort you over.”

**Notes for the Chapter:**

> Eridani: Their planet is almost completely covered in water, and thus their evolution is intrinsically connected to the ocean. Gills to allow for safer and longer underwater foraging along with retractable fins on their legs classify them as a semi-aquatic species. Moisture pads on the wrists store water, allowing for more land travel than their ancestors who were limited to living near water sources. Culture: in progress. Internal biology: unknown. Classification: peaceful, rarely leave their planet.
> 
> ^Zexion's notes: Individual seems to be an outlier in that he has been absent from his planet for most of his adult life. Omnivorous, but perhaps only due to life in space? Most land and air animals fascinate him.


End file.
